MONTREAL – Early imaging may be the best clue about seizure remission in children with early intractable seizures, according to findings from a population-based, retrospective cohort study.
Children who had uncontrolled seizures at 2 years and structural brain abnormalities had a 9% rate of becoming seizure free during a median follow-up period of 12 years. However, 60% of those with structurally normal brains eventually did become seizure free, despite an early history of intractability, Dr. Elaine Wirrell said at the 30th International Epilepsy Congress.
Dr. Elaine Wirrell
"While a significant minority of children with early medical intractability ultimately achieved seizure control without surgery, those with an abnormal imaging study did poorly," said Dr. Wirrell of the Mayo Clinic, Rochester, Minn. "For this subgroup, early surgical intervention is strongly advised to limit the comorbidities of ongoing, intractable seizures. Conversely, a cautious approach is suggested for those with normal imaging, as most will remit with time."
She and her colleagues examined medical intractability in a group of 381 children who were diagnosed with epilepsy during 1980-2009 and who were followed for a median of 12 years. Of these, 75 (20%) showed early medical intractability, defined as failing at least two antiepileptic medications or continuing to have seizures more often than every 6 months.
The children were a mean of 7 years old when their epilepsy began. Most (75%) had a focal onset, while 23% had a generalized onset. Onset for the remainder was unknown. The etiology was unknown in 54%, genetic in 23%, and structural or metabolic in the remainder.
Overall, 74 children underwent either MRI or CT, and a structural brain abnormality was present in 35. There were 40 children who had structurally normal brains. (One patient was known to have a familial absence syndrome ruling out a structural abnormality and did not undergo brain imaging.)
After a median follow-up of 12 years, 48 patients were still having seizures or had undergone brain surgery; 32 of these initially had abnormal brain imaging. Only three children with a structural brain abnormality were seizure free off or on medications at follow-up. A total of 24 who had normal brain structure eventually became seizure free.
More than half of the patients with an abnormality were surgical candidates because of the presence of a single focal or hemispheric lesion (16), tuberous sclerosis (3), or mesio-temporal sclerosis with periventricular leukomalacia (1). Of 16 who underwent surgery, 7 became seizure free. Five were able to discontinue all antiepileptic drugs.
In a multivariate analysis, neuroimaging was a significant predictor of seizure outcome.
"Imaging that is done properly is important," Dr. Wirrell said in an interview. "There is value with going on with a medication trial, but if one fails, it’s reasonable to have the discussion of possible surgery as we are starting the next."
Dr. Wirrell had no financial disclosures.